class People:
    title = "人类"

    def __init__(self, name, age):
        self.__name = name
        self.__age = age

    def print_age(self):
        print('%s: %s' % (self.__name, self.__age))

    def get_name(self):
        return self.__name

    def get_age(self):
        return self.__age

    def set_name(self, name):
        self.__name = name

    def set_age(self, age):
        self.__age = age

obj = People("jack", 18)
print(obj.get_name())
obj.set_name("tom")
print(obj.get_name())
